package com.feilong.taglib;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * @author yeeku.H.lee kongyeeku@163.com
 * @version 1.0 <br>
 *          Copyright (C), 2005-2008, yeeku.H.Lee <br>
 *          This program is protected by copyright laws. <br>
 *          Program Name: <br>
 *          Date:
 */
public class AuthImg extends HttpServlet{

	private static final long	serialVersionUID	= 248447040735730839L;

	private Font				mFont				= new Font("Arial Black", Font.PLAIN, 16);

	public void init() throws ServletException{
		super.init();
	}

	Color getRandColor(int fc,int bc){
		Random random = new Random();
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}

	public void service(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		response.setContentType("image/jpeg");
		int width = 100, height = 18;
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		Graphics g = image.getGraphics();
		Random random = new Random();
		g.setColor(getRandColor(200, 250));
		g.fillRect(1, 1, width - 1, height - 1);
		g.setColor(new Color(102, 102, 102));
		g.drawRect(0, 0, width - 1, height - 1);
		g.setFont(mFont);
		g.setColor(getRandColor(160, 200));
		for (int i = 0; i < 155; i++){
			int x = random.nextInt(width - 1);
			int y = random.nextInt(height - 1);
			int xl = random.nextInt(6) + 1;
			int yl = random.nextInt(12) + 1;
			g.drawLine(x, y, x + xl, y + yl);
		}
		for (int i = 0; i < 70; i++){
			int x = random.nextInt(width - 1);
			int y = random.nextInt(height - 1);
			int xl = random.nextInt(12) + 1;
			int yl = random.nextInt(6) + 1;
			g.drawLine(x, y, x - xl, y - yl);
		}
		String sRand = "";
		for (int i = 0; i < 6; i++){
			String tmp = getRandomChar();
			sRand += tmp;
			g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
			g.drawString(tmp, 15 * i + 10, 15);
		}
		HttpSession session = request.getSession(true);
		session.setAttribute("rand", sRand);
		g.dispose();
		ImageIO.write(image, "JPEG", response.getOutputStream());
	}

	private String getRandomChar(){
		int rand = (int) Math.round(Math.random() * 2);
		long itmp = 0;
		char ctmp = '\u0000';
		switch (rand) {
			case 1:
				itmp = Math.round(Math.random() * 25 + 65);
				ctmp = (char) itmp;
				return String.valueOf(ctmp);
			case 2:
				itmp = Math.round(Math.random() * 25 + 97);
				ctmp = (char) itmp;
				return String.valueOf(ctmp);
			default:
				itmp = Math.round(Math.random() * 9);
				return String.valueOf(itmp);
		}
	}
}
